When displaying an image, a display apparatus needs a gate driver on array (GOA) to drive the pixel units. The gate driver on array (also called shift register) includes multiple cascading shift register units, each of which is used to drive a line of pixel units. The multiple cascading shift register units realize line-by-line scan-driving of the multiple lines of pixel units of the display apparatus to display the image.
In the related art, a gate driver on array can scan all lines of pixel units in a display apparatus within the time of one frame. The charging time for each line of pixel units is determined by the frequency of a clock signal.
As the frequency and the duty ratio of the clock signal output from the clock signal terminal coupled to the shift register unit are fixed, when the gate driver on array drives the pixel units, the charging time for each line of pixel units is also fixed, and the driving manner is monotonous.